Pulverized-fuel burner



March 1a, 1%31. J VAN BRUNT PULVERIZED FUEL BURNER Filed Aug. 6, 1926INVENTOR ATTORNEYS with.

Patented Mar. 10, 1931 UNITED STATES PATENT OFFICE JOHN VAN BRUNT, OF

DELAWARE FLUSHING, NEW YORK, ASSIGNOR TO INTERNATIONAL CO]!!- BUSTIONENGINEERING CORPORATION,

OF NEW YORK, N. 'Y., A CORPORATION OF I PULVERIZED-FUEL BURNERApplication filed August 6, 1926. Serial No. 127,536.

This invention relates to pulverized fuel burners, and is particularlyuseful in the type of pulverized fuel combustion in which substantiallyall the air for combustion is admitted at the burner.

The main disadvantage with burners of this type heretofore used was that.it was found very difiicult to supply and thoroughly mix sufficient airwith the fuel for complete and eflicient combustion at various rates offiring. The primary object of the present invention is to provide anapparatus which will deliver air and fuel in the proper proportions atany rate of firing, and to deliver a stream of air and fuel alwaysthoroughly mixed, regardless of the rate of firing.

How the foregoing, together with such other objects and advantages asmay hereinafter appear, are realized will be clear from the followingdescription of the preferred embodiment of the invention known to me atpresent.

In the drawings:

Fig. 1 is a vertical longitudinal section of a burner constructed inaccordance with my invention;

Fig. 2 is an elevation taken on the line 22 of Fig. 1, showing the airinlet louvers or vanes in a partially open position, and

Fig. 3 is a view similar to Fig. 2, but showin the vanes in closedposition.

eferring now to the drawing, the fuel supply line is indicated by thereference numeral 1, and extends into the fuel nozzle proper 2, forminga slip connection there- The nozzle 2 has a flaring portion 3 at itsdelivery end in which a conical deflector 4 is positioned, and securedin some suitable manner, as by the bolts 5, to deliver the fuel in asheet substantially from the periphery of the nozzle. The deflector 4may be constructed of a metal cone filled with a refractory material,such as indicated by the reference numeral 6, to protect parts of thenozzle 2 from the intense heat of the furnace.

The burner, as a whole, is surrounded by a casing 7 extending partwaythrough the furnace wall 8, and is provided with an opening throughwhich the supply end of the nozzle extends with freedom of longitudinalmotion. A damper 9' controls the air admitted from the air supply line10, to the interior of the burner casing 7. A supplementary casing 11surrounds the burner nozzle 2, and is provided with an opening throughwhich the cylinder 12, secured to the delivery end of the nozzle, isfree to move. Air is admitted from the interior of easing 7 to theinterior of supplementary casing 11 through the opening 13, which iscontrolled by the auxiliary damper 14c.

A circumferential set of vanes 15 extends within the casing 7 from theopening 16, into the interior of the furnace, to the opening in thecasing 11 through which the delivery end of the nozzle extends, andforms, when the vanes are in closed position, a cylindrical passage fromthe nozzle into the combustion chamber. Each vane 15 has a pivot pin 17at each end thereof positioned near or at one edge. The pins 17 at theends of the. vanes toward the combustion chamber have bearings in thecasing 7 around the opening to the chamber, and the pins 17 at the otherends of the vanes have bearings in the casing 11 around the opening.through which the nozzle extends. The free edges of the vanes 15 havelink connections 19 to a ring 18 around the vanes, on rotation of whichthe amount of air admitted, from the interior of the housing 7 throughthe vanes, may be controlled (see Figs. 2 and 3). The ring 18 has asuitable link connection 24 to the exterior of the casing 7 for controlof the openings between the vanes 15, and has bearing means 25 securedto the casing 7 to keep the ring in a concentric position with relationto the vane bearings 17.

A burner nozzle control lever 20 is pivoted at 21, and has a double forkand pin connec tion 22, of a well known type, with the nozzle 2adjustment of the nozzle.

Openings 23 are provided between the periphery of the delivery end ofthe nozzle and its surrounding cylinder 12 for admission of air from theauxiliary casing 11 into the fuel stream.

In operation of the burner of the resent invention, pulverized coal is amitted providing for control of the longitudinal through the nozzle 2with substantially no more air than is sufficient for carrying purposes.If the furnace is being fired at a low rate, the nozzle may be moved, bymeans of the lever 20, toward the combustion chamber, the cylinder 12advancing through the opening in the casing 11 and thus blocking off apart of the vanes 15. The openings between the vanes 15 may also bereduced, or the vanes may be closed entirely for very low rates, inwhich instance all the air for combustion is admitted through theopenings 23. In the case of high rates of firing the nozzle with itscylinder 12 is moved away from the combustion chamber, thus exposing theentire surface of the openings between the vanes 15.

The vane construction admits the air substantially tangentially, causinga violent swirling of fuel and air, which results in complete andthorough admixture, and the vanes 15, together with the dampers 9 and14, admit of very accurate control of the air for all rates of firing.

Of course, it will be understood that the relative pressure conditionsare such that the streams of air entering between the louvers have atleast suflicient velocity to prevent any coal from dischargingperipherally into the casing 7. I prefer relatively high velocities ofsuch air to insure thorough admixture.

I claim 1. A burner for pulverized fuel furnaces vanced position,together with independent means for controlling the air admittedlongitudinally.

4. A burner for pulverized fuel furnaces comprising a casing having anair inlet and an opening into the furnace; a cylindrical set of louversin said casing, one end of which is adjacent said opening; asupplementary casing in said first mentioned casing having an air inletand an opening communicating with the other end of said cylindrical setof louvers; a nozzle having a cylindrical sleeve around its delivery andextending through said second mentioned opening into said cylindricalset of louvers; passages in said sleeve for admission of air from saidsupplementary easing into the fuel stream around the edge of saidnozzle; and means for moving said nozzle with its sleeve longitudinallywith respect to said set of louvers to control the air admissiontherethrough.

In testimony whereof I have hereunto signed my name.

JOHN VAN BRUN T.

comprising a cylindrical set of air admission louvers one end of whichopens into the furnace; a fuel nozzle extending into the other end ofsaid cylindrical set of louvers discharging therethrough into thefurnace; means for advancing and retracting said nozzle with respect tothe furnace; and means carried by said nozzle for blocking off a part ofthe air admission louvers when said nozzle is in advanced position.

2. A burner for pulverized fuel furnaces comprising in combination, anozzle adapted to discharge a stream of fuel, means for admitting airinto the fuel stream substantially tangentially thereto, means foradmitting air into the fuel stream substantially longitudinally thereto,means for advancing or retracting said nozzle toward or away from thefurnace and means carried by said nozzle for blocking oil a portion ofsaid'first mentioned air admission means when the nozzle is in advancedposition.

3. A burner for pulverized fuel furnaces comprising in combination, anozzle adapted to discharge a stream of fuel, means for ad mitting airinto the fuel stream substantially tangentially thereto, means foradmitting air into the fuel stream substantially longitudinally thereto,means for advancing or retracting said nozzle toward or away from thefurnace and means carried by said nozzle for blocking off a portion ofsaid first mentioned air admission means when the nozzle is in ad-

